They look like a standard image file; however, to create an icon, you must have a special software program capable of creating and saving an image in ICO format. The size of an icon will vary depending on the application it is associated with. Some will require a 16x16 pixel image and others may require a 32x32 pixel image. In addition, the number of required colors may be 16 or 256.
There are several kinds of icons which serve different purposes. Application icons are used in software programs such as Microsoft Office, as buttons and in tool bars. Website icons are used for navigation while using the Internet, like buttons displaying 'previous,' 'next' and 'back.' Desktop icons are for symbolizing various programs. Icons are actively used in instant messengers to display emotions or actions like happiness, waving and kissing, and to display identity or status of availability like away, available, busy and so on.
There are many web design icon sites that, with a price, help you design your own icon. These icon design sites have icon design groups that work from the look and feel of your web site or with any images; you give them, to design an icon compliant with multiple browsers. The icon design is available in different sizes like 256 colors, 32x32 and 16x16 pixel designs.
